fails:IO#sysread on a file reads the specified number of bytes from the file
fails:IO#sysread on a file reads the specified number of bytes from the file to the buffer
fails:IO#sysread on a file coerces the second argument to string and uses it as a buffer
fails:IO#sysread on a file advances the position of the file by the specified number of bytes
fails:IO#sysread on a file reads normally even when called immediately after a buffered IO#read
fails:IO#sysread on a file does not raise error if called after IO#read followed by IO#write
fails:IO#sysread on a file does not raise error if called after IO#read followed by IO#syswrite
fails:IO#sysread on a file reads updated content after the flushed buffered IO#write
fails:IO#sysread on a file raises IOError on closed stream
